Crystal Research and Technology最新文献

This study systematically investigates the impact of varying Pd content (0 at% to 50 at%) on the mechanical stability, elastic properties, and electronic structure of PdCu alloys using first-principles calculations based on density-functional theory. The results reveal that increasing Pd content leads to a linear increase in lattice constant and a decrease in structural stability, as indicated by binding energy and enthalpy of formation. Elastic modulus variations with Pd content are nonlinear, with distinct trends at low (<20 at%), intermediate (20–40 at%), and high (>40 at%) Pd contents. The electronic structure analysis shows that the bonding electrons are mainly concentrated between -5 and 0 eV, with resonance peaks contributed by Cu 3d and Pd 4d orbitals. Increasing Pd content elevates the density of states at the Fermi level, correlating with reduced structural stability. These findings provide insights into the composition–structure–performance relationships of PdCu alloys, crucial for their application in extreme environments.

Density functional theory (DFT) is employed by using Perdew–Burke–Ernzerhof (PBE) function in the generalized gradient approximation (GGA) framework to investigate the thermodynamic, electronic, mechanical, structural, elastic, and optical properties of the Dion Jacobson (DJ) family member (LiBiNb₂O₇ and FrBiNb₂O₇) compounds. Thermodynamic properties have been determined by using the density function perturbation theory (DFPT) technique. In thermodynamic properties of LiBiNb₂O₇ and FrBiNb₂O₇, distinct zero-point energies 1.4025 and 1.2032 eV, respectively, are computed. For both compounds at 600 K, the heat capacity (Cv) approaches the Dulong-Petit limit values. The compounds have presented the indirect band gaps of 2.548 and 2.563 eV, respectively, indicating a semiconductor nature, which are ideal for optoelectronic applications. Highest peak values of optical conductivity (6–7 fs⁻¹), absorption coefficient (10⁵ cm⁻¹), dielectric function (5–10), and refractive index (3–3.5) are reported in visible and near UV regions. Elastic constants are used to calculate mechanical properties, which further confirm the mechanical stability of these compounds by Born stability criteria and have predicted the ductile nature of these compounds by B/G > 1.75. Moreover, the mechanical properties show their applicability for flexible optoelectronic applications. This article provides useful information about the strategy and advancement of compounds appropriate for next-generation solar cell devices.

The inverse design of materials represents a pivotal technology in the domains of materials science and information engineering. It facilitates the prediction of material properties and structures from desired functionality, thereby accelerating the development of new materials. Nevertheless, conventional material design methodologies frequently necessitate the utilization of extensive computational simulations and experiments, which are inherently time-consuming and resource-intensive. A novel approach to materials inverse design is put forth, namely a rotationally invariant crystallographic representation (RICR) coupled with a variational autoencoder (VAE) generative model. The RICR effectively encapsulates the salient features of the crystal structure while preserving rotational invariance through the incorporation of rotational coordinate features. By conducting inverse design experiments on data from the Materials Project database, new crystal materials with user-specified band gaps and formation energies are successfully design and validated. The results demonstrate that RICR achieves improvements in reconstruction accuracy, performance in mapping regression branch attributes, and the success rate of generating target crystal designs. These findings indicate the effectiveness of RICR in inverse materials design and suggest that this method can provide robust theoretical support for inverse design across diverse materials, thereby advancing the development and innovation of materials science.

In order to improve the hygroscopic stability of berberine(BER) and maintain its solubility, an unreported berberine-benzenesulfonic acid (BER-H₂O-BSA) pharmaceutical salt is designed and synthesized through incorporating benzenesulfonic acid (BSA) to form charge-assisted hydrogen (CAHBs) via water bridging. To the best knowledge, the building unit of BER-H₂O-BSA is the first asymmetric unit that connects BER and BSA through hydrogen bonds and CAHBs formed with water bridging. These adjacent asymmetric units are further linked by hydrogen bonds C10-H10···O10, leading to the generation of the cyclic synthetic unit R⁶₆(22). As expected, the hygroscopic stability and permeability of BER-H₂O-BSA have been significantly improved compared to BERCl. This study underscores the potential of BERCl to form a pharmaceutical salt by introducing benzenesulfonate, thereby optimizing its physicochemical properties and providing a theoretical basis for future advancements in the physicochemical properties of parent berberine-like compounds.

In this study, the β' phase in Mg-Gd-Y-Ag alloy is characterized at the atomic scale using a Cs-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Meanwhile, the influence of Ag doping with different concentrations on the precipitation of β“-phase configurations is investigated. The calculation of formation enthalpy indicates that an appropriate amount of Ag doping can optimize the atomic arrangement, reduce the nucleation barrier, and thus promote nucleation. The results of the adhesion and interfacial energy show that Ag doping changed the atomic bonding, structural order within the material, and it makes the system unstable. In terms of β” nucleation, the interfacial energy directly affects the nucleation potential barrier. A low interfacial energy is favorable for β' nucleation. Ag doping increases the interfacial energy, thereby raising the nucleation potential barrier and inhibiting β' nucleation. Moreover, the higher the Ag concentration, the more pronounced the inhibitory effect. The electronic structure properties show that within a specific energy range, the electrons in the 4d orbitals of Ag will transfer to the 5f orbitals of Gd. This electron transfer enhances the atomic bonding within the crystal, forms a more stable electronic structure, and further improves the stability of the crystal.

In this work, the electronic structures and optical features of the SrZnSi and SrZnGe half-Heuslers are elucidated using the GGA-PBE approach and the TB-mBJ potential. The formation energies are negative, suggesting that these Heuslers appear to be thermodynamically stable. Both materials are more stable in the type II cubic structure, and their structural constants are consistent with the experimental data, and they satisfy the stability criteria with brittle behavior. In ultraviolet (UV), maximum reflectivity and absorption are found for both materials with directgaps of 1.0 and 0.535 eV, respectively, for SrZnSi and SrZnGe. Therefore, the SrZnSi and SrZnGe are potentially suitable materials for photovoltaic applications.

Aiming at the problems of low crystallization rate and uneven particle size during evaporative crystallization of ammonium sulfate mother liquor (a by-product of ammonia desulfurization of sintered flue gas), this study investigated via orthogonal tests the effects of evaporation temperature, pH, stirring rate, and calcium sulfate addition on crystallization amount, average particle size, and coefficient of variation (C.V.). The results showed: For crystallization amount, the influence degree was evaporation temperature>pH>stirring rate>calcium sulfate addition; for average particle size, it was stirring rate>pH>evaporation temperature>calcium sulfate addition; for C.V. value, it was stirring rate>pH>calcium sulfate addition>evaporation temperature. Crystal morphologies included hexahedral, columnar, lamellar, etc., with aggregation under some conditions. Crystals contained calcium, nitrogen, oxygen, and sulfur elements(Ca, N, O, S); Ca content increased with calcium sulfate addition. Ammonium sulfate crystals' diffraction peaks matched pure ammonium sulfate, with the highest peaks at pH 5.0, 250 rpm stirring, 3500 mg·L⁻¹ calcium sulfate, and 333.15K.

This study reports a composite hydrogel composed of ginseng peptides (GGP), cellulose nanocrystals (CNC), and menthol@β-cyclodextrin (β-CD@Menthol). Characterization confirms the successful inclusion of menthol, enhances crystallinity, and a uniform porous structure. The β-CD@Menthol/GGP@CNC hydrogel exhibits high mechanical strength (elongation 1495.4%, toughness 3320.0 kJ m⁻³), strong antioxidant activity (ABTS scavenging 90.9%), excellent swelling capacity (1198.3% in saline), and effective antibacterial effects against Escherichia coli and Staphylococcus aureus. These properties highlight its promise as a multifunctional wound dressing to combat infection and oxidative stress in chronic wounds.

This study employs numerical simulation to analyze the coupled effects of rotation speed difference (Δω) and growth rate (V_g) on thermal stress and oxygen-related defect behavior during Czochralski silicon single crystal growth. The results indicate that increasing Δω enhances shear convection, raises the stress level at the solid–liquid interface, and promotes vacancy formation; when Δω exceeds 12 rpm, vacancy concentration increases linearly, significantly enhancing the formation of VO and VO₂ complexes. Under the same Δω increase, accelerating the crystal rotation leads to a greater rise in VO_x concentration compared to accelerating the crucible. As V_g increases, the S–L interface shifts upward, temperature gradients and thermal stress intensify simultaneously, and the concentrations of VO and VO₂ increase by 26.1% and 25.88%, respectively. Therefore, Δω and V_g exhibit a strong synergistic regulatory effect on the thermal field and point defect evolution. Improper control may lead to excessive generation and accumulation of VO_x defects, ultimately degrading crystal quality. Hence, in practical CZ crystal growth, it is essential to optimize the coordination of Δω and V_g to achieve both high growth efficiency and effective defect suppression.